Static mixers for the mixing of at least two flowable components are described, for example, in EP-A-0 749 776 and in EP-A-0 815 929. These very compact mixers provide good mixing results, in particular also on the mixing of high-viscosity materials such as sealing compounds, two-component foams or two-component adhesives, despite a simple, material-saving design of their mixer structure. Such static mixers are usually designed for single use and are frequently used for products to be hardened in which the mixer can practically no longer be cleaned.
In some applications in which such static mixers are used, it is desirable to spray the two components onto a substrate after their mixing in the static mixer. For this purpose, the mixed components are atomized at the outlet of the mixer by the action of a medium such as air and can then be applied to the desired substrate in the form of a spray jet or spray mist. Such an apparatus is disclosed, for example, in U.S. Pat. No. 6,951,310.
In this apparatus, a tubular mixer housing is provided which receives the mixing element for the static mixing and which has an external thread at one end onto which a ring-shaped nozzle body is screwed. The nozzle body likewise has an external thread. A conical atomizer element which has a plurality of grooves extending in the longitudinal direction on its cone surface is placed onto the end of the mixing element which projects out of the mixer housing. A cap is pushed over this atomizer element whose inner surface is likewise of conical design so that it contacts the cone surface of the atomizer element. The grooves consequently form flow channels between the atomizer element and the cap. The cap is fixed to the nozzle body together with the atomizer element by means of a retaining nut which is screwed onto the external thread of the nozzle body. The nozzle body has a connection for compressed air. In operation, the compressed air flows out of the nozzle body through the flow channels between the atomizer element and the cap and atomizes the material being discharged from the mixing element.
Even if this apparatus has absolutely proved to be fully functional, its structure is very complex and the installation is complicated and/or expensive so that the apparatus is in particular not very cost-effective with respect to the single use.
Starting from this prior art, it is therefore an object of the invention to propose a particularly simple static spray mixer for the mixing and spraying of at least two flowable components which is cost-effective in its manufacture and enables an efficient mixing or thorough mixing and atomization of the components.